May I present to you Fatetale!Gaster aka. Despair~
I thought he was the best decision to create first after Frisk, Chara ( who still needs a fullbody ) and Sans, since Fate was talking about him the most in all the asks I’ve received.

So this guy is a scientist and he’s trying to find a faster, more efficient way to find everyones fate.
Well he made a few experiments and let’s just say that two of these experiments were Fate and Papyrus.
But he didn’t “throw them away” because they were failed experiments, like Fate thought.
He was waiting for the both of them to be old enough to take care of themselves and then set them out in Snowdin to see if they would find their fate faster than others. To his regret they didn’t. 
That’s when he started to make experiments with his own soul and shut himself off from the rest of the universe. He thought that it would make more sense to work on his own fate all by himself after he failed on his sons.

I’m still thinking about if he should find his fate in the comic or not. But he would’ve probably found it through one of his experiments. Maybe even through Fate when he sees that he’s escaped from their universe to find his own fate.
I haven’t decided on that yet-

Thirteen Kinds of Despair by Lemony Snicket

You may be interested to know that I have categorized thirteen kinds of despair, listed here for your convenience… and arranged by time-of-day, so with planning you may experience all thirteen despairs in a single twenty-four hour period.

The first kind of despair is the suspicion that there is no safe territory outside the warm confines of one’s bedclothes.

The second kind of despair is the sense that even the most elegant of breakfasts is fragile resistance to the oncoming day.

The third kind of despair is finding life as shifty and indiscernible as the Rorschach of crumbs on your plate.

The fourth kind of despair is when the tea is so hot you must leave it alone until it is far too cold.

The fifth kind of despair is the knowledge that with the sun overhead, your shadow has vanished and there is no place to hide.

The sixth kind of despair is when you realize you must close the book you are reading and reluctantly participate in something or other.

The seventh kind of despair is that the sun has set on another day and so little has been done.

The eighth kind of despair is burning dinner in the oven.

The ninth kind of despair is the realization that a bad dinner still creates dirty dishes.

The tenth kind of despair is the presentiment that a darkening sky brings darkening times.

The eleventh kind of despair is the inkling that an evening should have been better spent but that it is almost bedtime.

The twelfth kind of despair is the knowledge that countless others are sleepless with you.

The thirteenth kind of despair occurs at every moment, waking or sleeping, and surely this needs no explanation.

I’ve been crying all day
It hurts because I know you wouldn’t be there to comfort me,
To tell me it’s gonna be okay,
I wouldn’t be able to hear your voice,
I won’t be able to be okay,
Because you’re the reason, but I still love you,
And I still miss you.
—  //9:28, i don’t think i’ll be able to move on